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1.
PLoS Genet ; 19(7): e1010849, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37463168

RESUMO

Epithelial tissues can be polarized along two axes: in addition to apical-basal polarity they are often also polarized within the plane of the epithelium, known as planar cell polarity (PCP). PCP depends upon the conserved Wnt/Frizzled (Fz) signaling factors, including Fz itself and Van Gogh (Vang/Vangl in mammals). Here, taking advantage of the complementary features of Drosophila wing and mouse skin PCP establishment, we dissect how Vang/Vangl phosphorylation on a specific conserved tyrosine residue affects its interaction with two cytoplasmic core PCP factors, Dishevelled (Dsh/Dvl1-3 in mammals) and Prickle (Pk/Pk1-3). We demonstrate that Pk and Dsh/Dvl bind to Vang/Vangl in an overlapping region centered around this tyrosine. Strikingly, Vang/Vangl phosphorylation promotes its binding to Prickle, a key effector of the Vang/Vangl complex, and inhibits its interaction with Dishevelled. Thus phosphorylation of this tyrosine appears to promote the formation of the mature Vang/Vangl-Pk complex during PCP establishment and conversely it inhibits the Vang interaction with the antagonistic effector Dishevelled. Intriguingly, the phosphorylation state of this tyrosine might thus serve as a switch between transient interactions with Dishevelled and stable formation of Vang-Pk complexes during PCP establishment.


Assuntos
Polaridade Celular , Proteínas Desgrenhadas , Proteínas de Drosophila , Proteínas de Membrana , Animais , Camundongos , Polaridade Celular/genética , Proteínas Desgrenhadas/genética , Proteínas Desgrenhadas/metabolismo , Drosophila/genética , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Receptores Frizzled/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fosforilação
2.
J Trauma Acute Care Surg ; 95(2S Suppl 1): S13-S18, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37246291

RESUMO

OBJECTIVES: The objective of this study is to describe the United States and allied military medical response during the withdrawal from Afghanistan. BACKGROUND: The military withdrawal from Afghanistan concluded with severe hostilities resulting in numerous civilian and military casualties. The clinical care provided by coalition forces capitalized on decades of lessons learned and enabled unprecedented accomplishments. METHODS: In this retrospective, observational analysis, casualty numbers, and operative information was collected and reported from military medical assets in Kabul, Afghanistan. The continuum of medical care and the trauma system, from the point of injury back to the United States was captured and described. RESULTS: Prior to a large suicide bombing resulting in a mass casualty event, the international medical teams managed distinct 45 trauma incidents involving nearly 200 combat and non-combat civilian and military patients over the preceding 3 months. Military medical personnel treated 63 casualties from the Kabul airport suicide attack and performed 15 trauma operations. US air transport teams evacuated 37 patients within 15 hours of the attack. CONCLUSION: Lessons learned from the last 20 years of combat casualty care were successfully implemented during the culmination of the Afghanistan conflict. Ultimately, the effort, teamwork, and system adaptability exemplify not only the attitudes and character of service members who provide modern combat casualty care but also the paramount importance of the battlefield learning health care system. A continued posture to maintain military surgical preparedness in unique environments remain crucial as the US military prepares for the future.Retrospective observational analysis. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level V.


Assuntos
Incidentes com Feridos em Massa , Medicina Militar , Militares , Ferimentos e Lesões , Humanos , Estados Unidos , Estudos Retrospectivos , Afeganistão , Medicina Militar/métodos , Campanha Afegã de 2001-
3.
Orphanet J Rare Dis ; 17(1): 266, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35840992

RESUMO

BACKGROUND: Fabry Disease (FD) is a rare X-linked metabolic lysosomal disorder. FD has a broad range of symptoms which vary markedly between patients. The heterogenous nature of the disease makes diagnosis difficult for health care professionals (HCPs), which in turn has a significant effect on the patient's quality of life (QoL). As few adolescent patients are eligible for treatment, to date there has been little published data on the burden of disease and impact of treatment on these patients and their caregivers. This study was developed to provide some insight into these groups. METHODS: An online-based survey was performed to gather further insights on the burden of FD in 14 adolescents aged 12-15 years old across three European countries, from the perspective of the patients, caregivers and HCPs. RESULTS: Symptom burden was found to be high in the adolescent population, with 'pain' and 'intolerance to heat or cold' commonly reported symptoms, both by patients and to HCPs. Eleven of the 14 patients surveyed were receiving enzyme replacement therapy (ERT), with their post-ERT symptomology showing improvement when compared to symptoms before receiving ERT. The majority of caregivers believe their child's overall health has improved since starting ERT. While there was a positive outlook towards ERT noted by the patients and caregivers, 4/5 HCPs believed there is 'a need for more efficacious treatment options' and all HCPs noted that there is 'a need for more manageable treatment options'. FD was shown to place a burden on caregivers, who reported feelings of guilt and absences from work. CONCLUSIONS: Data show there is a significant symptom burden for the adolescent, which affects their QoL and mental health, as well as placing a burden on the wider family. While ERT is an effective treatment and provides symptom relief for many of the respondents in the survey, they still reported symptom burden. Additionally, there was reporting of reluctance to engage in treatment or difficulties associated with the treatment. Heterogeneity in symptom presentation suggests that the treatment regimen needs to be tailored to the individual. Physicians therefore need to have a choice of treatment options available to help them manage symptoms and disease where the benefit to risk ratio is in favour of undergoing treatment.


Assuntos
Doença de Fabry , Adolescente , Cuidadores/psicologia , Criança , Terapia de Reposição de Enzimas , Doença de Fabry/tratamento farmacológico , Humanos , Qualidade de Vida , Inquéritos e Questionários
4.
Elife ; 92020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32234212

RESUMO

Planar cell polarity (PCP) and neural tube defects (NTDs) are linked, with a subset of NTD patients found to harbor mutations in PCP genes, but there is limited data on whether these mutations disrupt PCP signaling in vivo. The core PCP gene Van Gogh (Vang), Vangl1/2 in mammals, is the most specific for PCP. We thus addressed potential causality of NTD-associated Vangl1/2 mutations, from either mouse or human patients, in Drosophila allowing intricate analysis of the PCP pathway. Introducing the respective mammalian mutations into Drosophila Vang revealed defective phenotypic and functional behaviors, with changes to Vang localization, post-translational modification, and mechanistic function, such as its ability to interact with PCP effectors. Our findings provide mechanistic insight into how different mammalian mutations contribute to developmental disorders and strengthen the link between PCP and NTD. Importantly, analyses of the human mutations revealed that each is a causative factor for the associated NTD.


As an embryo develops, its cells must work together to build mature tissues and organs. During the formation of the nervous system, for example, a sheet of cells destined to become the brain and spinal cord folds up into a tube spanning the length of the embryo. Normally, this tube ­ known as the 'neural tube' ­ zips up, and the cells that will eventually become skin and other surrounding tissues close in over it. If the neural tube does not close completely, different parts of the spinal cord or brain can remain unprotected. This can cause diseases called neural tube defects, such as spina bifida, which is characterized by holes in the backbone exposing the spinal cord and surrounding membranes. Patients with neural tube defects can have similar genetic mutations, for example, in the genes controlling a process called "planar cell polarity", or PCP for short. Cells arranged in flat sheets use the PCP process to sense direction, and it is this process that allows structures, such as the scales on a fish or the hairs on a mouse, to all point in the same direction. PCP is also important in embryonic development: sheets of cells that can sense direction correctly can therefore move collectively to complete complex tasks (such as closing the neural tube). However, no-one knew whether the specific PCP gene mutations implicated in neural tube defects in humans actually affected the cells' ability to sense direction, or indeed whether they were even involved in causing the diseases. Humphries et al. set out to find out more about these mutations using fruit flies as a model system. The fruit fly is widely used to study the genes and signals involved in direction sensing, especially PCP. Problems with PCP produce easily measurable changes in the wing and eye, showing what went wrong and how badly. Humphries et al. genetically engineered fruit flies to have the same mutations as human patients and revealed that these mutations did indeed alter cells' ability to sense direction. These experiments also showed that each mutation did so in a different way, and with varying severity. This explained why the same mutations caused different levels of neural defects in mice (which are commonly used to study human diseases) and suggests that they might contribute to neural tube disorders in humans. These results show potential connections between neural tube defects and direction sensing in cells. In the future, this study and follow-up work could help researchers to understand what types of mutation have the most impact, which may eventually allow doctors to better predict who is most at risk of being affected by these conditions.


Assuntos
Proteínas de Transporte/genética , Polaridade Celular/fisiologia , Proteínas de Drosophila/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana/genética , Mutação , Defeitos do Tubo Neural/genética , Animais , Modelos Animais de Doenças , Drosophila , Humanos , Camundongos , Defeitos do Tubo Neural/etiologia
5.
J Cell Sci ; 133(7)2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32094266

RESUMO

Efficient migration on adhesive surfaces involves the protrusion of lamellipodial actin networks and their subsequent stabilization by nascent adhesions. The actin-binding protein lamellipodin (Lpd) is thought to play a critical role in lamellipodium protrusion, by delivering Ena/VASP proteins onto the growing plus ends of actin filaments and by interacting with the WAVE regulatory complex, an activator of the Arp2/3 complex, at the leading edge. Using B16-F1 melanoma cell lines, we demonstrate that genetic ablation of Lpd compromises protrusion efficiency and coincident cell migration without altering essential parameters of lamellipodia, including their maximal rate of forward advancement and actin polymerization. We also confirmed lamellipodia and migration phenotypes with CRISPR/Cas9-mediated Lpd knockout Rat2 fibroblasts, excluding cell type-specific effects. Moreover, computer-aided analysis of cell-edge morphodynamics on B16-F1 cell lamellipodia revealed that loss of Lpd correlates with reduced temporal protrusion maintenance as a prerequisite of nascent adhesion formation. We conclude that Lpd optimizes protrusion and nascent adhesion formation by counteracting frequent, chaotic retraction and membrane ruffling.This article has an associated First Person interview with the first author of the paper.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina , Pseudópodes , Citoesqueleto de Actina , Complexo 2-3 de Proteínas Relacionadas à Actina/genética , Actinas/genética , Adesão Celular , Movimento Celular
6.
Hepatology ; 71(2): 549-568, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31215069

RESUMO

Cancer cells undergo metabolic adaptation to sustain uncontrolled proliferation. Aerobic glycolysis and glutaminolysis are two of the most essential characteristics of cancer metabolic reprogramming. Hyperactivated phosphoinositide 3-kinase (PI3K)/Akt serine/threonine kinase (Akt) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathways play central roles in cancer cell metabolic adaptation given that their downstream effectors, such as Akt and c-Myc, control most of the glycolytic and glutaminolysis genes. Here, we report that the cytosolic flavoprotein, NAD(P)H quinone dehydrogenase 1 (Nqo1), is strongly overexpressed in mouse and human hepatocellular carcinoma (HCC). Knockdown of Nqo1 enhanced activity of the serine/threonine phosphatase, protein phosphatase 2A, which operates at the intersection of the PI3K/Akt and MAPK/ERK pathways and dephosphorylates and inactivates pyruvate dehydrogenase kinase 1, Akt, Raf, mitogen-activated protein kinase kinase, and ERK1/2. Nqo1 ablation also induced the expression of phosphatase and tensin homolog, a dual protein/lipid phosphatase that blocks PI3K/Akt signaling, through the ERK/cAMP-responsive element-binding protein/c-Jun pathway. Together, Nqo1 ablation triggered simultaneous inhibition of the PI3K/Akt and MAPK/ERK pathways, suppressed the expression of glycolysis and glutaminolysis genes and blocked metabolic adaptation in liver cancer cells. Conversely, Nqo1 overexpression caused hyperactivation of the PI3K/Akt and MAPK/ERK pathways and promoted metabolic adaptation. Conclusion: In conclusion, Nqo1 functions as an upstream activator of both the PI3K/Akt and MAPK/ERK pathways in liver cancer cells, and Nqo1 ablation blocked metabolic adaptation and inhibited liver cancer cell proliferation and HCC growth in mice. Therefore, our results suggest that Nqo1 may function as a therapeutic target to inhibit liver cancer cell proliferation and inhibit HCC.


Assuntos
Carcinoma Hepatocelular/enzimologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Neoplasias Hepáticas/enzimologia , NAD(P)H Desidrogenase (Quinona)/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Animais , Carcinoma Hepatocelular/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Transdução de Sinais
7.
J Surg Case Rep ; 2019(1): rjy342, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30631421

RESUMO

Internal hernia is a rare cause of small bowel obstruction; even more rare is one that occurs through a sigmoid epiploica defect. There have been only two previously reported cases from this etiology, but both were without the advantage of high-resolution imaging. We report the first color representation of this pathology, along with the first video recording of the internal hernia reduction. While this is a rare case, it is an important diagnosis to consider in the differential for patients presenting with a small bowel obstruction, with no previous abdominal surgeries or clinical findings of extra-abdominal hernias.

8.
Mil Med ; 183(suppl_2): 98-100, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30189065

RESUMO

Unlike penetrating abdominal injuries where the decision to operate is relatively straight forward, those combat casualties that sustain blunt abdominal trauma offer more of a diagnostic and clinical challenge. For unstable patients with a positive focused abdominal sonography in trauma or diagnostic peritoneal lavage, exploratory laparotomy should be undertaken immediately. All grade IV-V splenic injuries should undergo splenectomy, patients undergoing attempted splenic salvage should be monitored in the Role 3 facility and embolization of such splenic injuries may be considered if available. Patients who fail non-operative management of the spleen require splenectomy at the Role 3 prior to aeromedical evacuation. Overwhelming post-splenectomy infection is a serious disease that can progress from a mild flu-like illness to fulminant sepsis in a short period of time. Although relatively rare, it has a high mortality rate with delayed or inadequate treatment. All splenectomized patients and those deemed to be functionally asplenic should be vaccinated within 14 days from splenectomy and prior to aeromedical evacuation.


Assuntos
Esplenectomia/métodos , Vacinação/métodos , Ferimentos não Penetrantes/complicações , Traumatismos Abdominais/complicações , Traumatismos Abdominais/cirurgia , Guias como Assunto , Humanos , Baço/lesões , Baço/fisiopatologia , Esplenectomia/efeitos adversos , Ultrassonografia/métodos , Vacinação/tendências , Ferimentos não Penetrantes/cirurgia
9.
Patient Saf Surg ; 12: 17, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29977337

RESUMO

BACKGROUND: The Joint Trauma System has demonstrated improved outcomes through coordinated research and process improvement programs. With fewer combat trauma patients, our military American College of Surgeons level 2 trauma center's ability to maintain a strong trauma Process Improvement (PI) program has become difficult. As emergency general surgery (EGS) patients are similar to trauma patients, our Trauma and Acute Care Surgery (TACS) service developed an EGS PI program analogous to what is done in trauma. We describe the implementation of our novel EGS PI program and its effect on institutional PI proficiency. METHODS: An EGS registry was developed in 2013. Inclusion criteria were based on AAST published literature. In 2015, EGS registrar and PI coordinator positions were developed and filled with existing trauma staff. A formal EGS PI program began January 1, 2016. Pre- and post-program data was compared to determine the effect including EGS PI events had on increasing yield into our trauma PI program. RESULTS: In 2016, TACS saw 1001 EGS consults. Four hundred forty-four met criteria for registry inclusion. Eighty-two patients had 131 PI events; re-admission within 30 days, unplanned therapeutic intervention, and unplanned ICU admission were the most common events. Capture of EGS PI events yielded a 49% increase compared with 2015. CONCLUSION: Overall patient volume and PI events post EGS PI program initiation exceeded those prior to implementation. These data suggest that extending trauma PI principles to EGS may be beneficial in maintaining inter-war military and/or lower volume trauma center readiness.

10.
Surg Endosc ; 32(10): 4321-4328, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29967995

RESUMO

INTRODUCTION: Decreasing combat-based admissions to our military facility have made it difficult to maintain a robust trauma process improvement (PI) program. Since emergency general surgery (EGS) and trauma patients share similarities, we merged the care of our EGS and trauma patients into one acute care surgery (ACS) team. An EGS PI program was developed based on trauma PI principles to facilitate continued identification of opportunities for improvement despite our decline in trauma admissions. Analysis of the first 18 months of combined ACS PI data is presented. METHODS: EGS registry inclusion criteria was based on published Association for the Surgery of Trauma's recommendations. Program components and PI categories were based on our existing trauma PI program. Dedicated coordinators actively reviewed and cataloged patient care and outcomes. Deviations from standard practice patterns, unplanned interventions, and other complications were abstracted, categorized, and evaluated through levels of review similar to accepted trauma PI principles. Data for the first six quarters were collated and trends were analyzed. RESULTS: Over 18 months, 696 EGS patients met registry inclusion criteria, with 468 patients (67%) undergoing operative intervention. Over the same time, 353 trauma patients were admitted with 158 undergoing operative intervention (56.4%). Of the 696 EGS patients and 353 trauma patients, 226 (32%) and 243 (69%) PI events were identified, respectively. Common events included unplanned therapies, re-admissions, and unplanned ICU admissions. Based on analysis of all events, four new areas for improvement initiatives were identified. Results of these initiatives included implementation of a multi-disciplinary EGS PI committee, consensus protocols, and departmental and hospital-wide actions. CONCLUSION: In an 18-month period, integration of our EGS patients into a novel, combined ACS PI program facilitated recognition of an additional 226 PI events and provided a substrate for continued improvements in patient care.


Assuntos
Cirurgia Geral/normas , Hospitais Militares/normas , Melhoria de Qualidade , Centros de Traumatologia/normas , Cuidados Críticos , Humanos , Militares , Sistema de Registros , Estados Unidos
11.
PLoS Genet ; 14(1): e1007153, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29309414

RESUMO

AKAP200 is a Drosophila melanogaster member of the "A Kinase Associated Protein" family of scaffolding proteins, known for their role in the spatial and temporal regulation of Protein Kinase A (PKA) in multiple signaling contexts. Here, we demonstrate an unexpected function of AKAP200 in promoting Notch protein stability. In Drosophila, AKAP200 loss-of-function (LOF) mutants show phenotypes that resemble Notch LOF defects, including eye patterning and sensory organ specification defects. Through genetic interactions, we demonstrate that AKAP200 interacts positively with Notch in both the eye and the thorax. We further show that AKAP200 is part of a physical complex with Notch. Biochemical studies reveal that AKAP200 stabilizes endogenous Notch protein, and that it limits ubiquitination of Notch. Specifically, our genetic and biochemical evidence indicates that AKAP200 protects Notch from the E3-ubiquitin ligase Cbl, which targets Notch to the lysosomal pathway. Indeed, we demonstrate that the effect of AKAP200 on Notch levels depends on the lysosome. Interestingly, this function of AKAP200 is fully independent of its role in PKA signaling and independent of its ability to bind PKA. Taken together, our data indicate that AKAP200 is a novel tissue specific posttranslational regulator of Notch, maintaining high Notch protein levels and thus promoting Notch signaling.


Assuntos
Proteínas de Ancoragem à Quinase A/fisiologia , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Drosophila melanogaster , Lisossomos/metabolismo , Proteínas de Membrana/fisiologia , Proteólise , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Receptores Notch/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Animais , Animais Geneticamente Modificados , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/metabolismo , Larva , Proteínas de Membrana/genética , Estabilidade Proteica , Transdução de Sinais/genética , Asas de Animais/crescimento & desenvolvimento , Asas de Animais/metabolismo
12.
Curr Opin Cell Biol ; 51: 110-116, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29289896

RESUMO

Planar cell polarity (PCP) provides positional information to direct tissue patterning and morphogenesis. While much of the molecular detail of the pathway has been delineated in Drosophila, ensuing studies have shown considerable conservation of both the components and mechanisms of signaling in vertebrates. A recognized feature of PCP is the asymmetric localization of components that translates a global directional cue into a polarized downstream output. Here we discuss recent advances in the PCP field, from the organization of these asymmetric complexes to their upstream directional regulation by Wnt ligands. We also discuss the impact of Wnt/PCP signaling in disease and more specifically an emerging role in cancer progression.


Assuntos
Polaridade Celular/fisiologia , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Neoplasias/genética , Animais , Humanos , Transdução de Sinais
13.
Nat Microbiol ; 1(10): 16141, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27670116

RESUMO

During its egress, vaccinia virus transiently recruits AP-2 and clathrin after fusion with the plasma membrane. This recruitment polarizes the viral protein A36 beneath the virus, enhancing actin polymerization and the spread of infection. We now demonstrate that three NPF motifs in the C-terminus of A36 recruit AP-2 and clathrin by interacting directly with the Epsin15 homology domains of Eps15 and intersectin-1. A36 is the first identified viral NPF motif containing protein shown to interact with endocytic machinery. Vaccinia still induces actin tails in the absence of the A36 NPF motifs. Their loss, however, reduces the cell-to-cell spread of vaccinia. This is due to a significant reduction in virus release from infected cells, as the lack of intersectin-1 recruitment leads to a loss of Cdc42 activation, impairing N-WASP-driven Arp2/3-mediated actin polymerization. Our results suggest that initial A36-mediated virus release plays a more important role than A36-driven super-repulsion in promoting the cell-to-cell spread of vaccinia.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Motivos de Aminoácidos , Vaccinia virus/fisiologia , Proteínas Estruturais Virais/metabolismo , Liberação de Vírus , Actinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Clatrina/metabolismo , Células HeLa , Interações Hospedeiro-Patógeno , Humanos , Ligação Proteica , Vaccinia virus/química , Vaccinia virus/genética , Proteínas Estruturais Virais/química , Proteínas Estruturais Virais/genética , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo
14.
Surg Technol Int ; 27: 19-30, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26680376

RESUMO

Laparoscopy using miniature (2-3.5 mm) instruments was introduced in the late 1980s and early 1990s. Though mini laparoscopy (Mini) created new opportunities for surgical diagnosis and therapy, the limitations of early instruments inhibited widespread adoption. This is no longer the case. Mini is enjoying a renaissance, due to several factors: the maturation of minimally invasive surgery (MIS), the failure of laparoendoscopic single-site surgery (LESS) and natural orifice transluminal endoscopic surgery (NOTES) platforms to achieve early expectations, and the recent significant improvements in Mini instrument functionality and durability. As a result, Mini is being increasingly applied to pediatric and adult procedures across specialties. To assess the current status of Mini laparoscopy, the Society of Laparoendoscopic Surgeons (SLS) and the Florida Hospital Nicholson Center convened an international symposium in February 2015. This report shares highlights from that symposium, "Big Operations Using Mini Instruments."


Assuntos
Laparoscópios , Laparoscopia/instrumentação , Miniaturização/instrumentação , Cirurgia Endoscópica por Orifício Natural/instrumentação , Humanos
16.
J Cell Sci ; 127(Pt 3): 673-85, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24284073

RESUMO

Vaccinia virus enhances its cell-to-cell spread by inducing Arp2/3-dependent actin polymerisation. This process is initiated by Src- and Abl-mediated phosphorylation of the viral transmembrane protein A36, leading to recruitment of a signalling network consisting of Grb2, Nck, WIP and N-WASP. Nck is a potent activator of N-WASP-Arp2/3-dependent actin polymerisation. However, recent observations demonstrate that an interaction between Nck and N-WASP is not required for vaccinia actin tail formation. We found that Cdc42 cooperates with Nck to promote actin tail formation by stabilising N-WASP beneath the virus. Cdc42 activation is mediated by the Rho guanine-nucleotide-exchange factor (GEF) intersectin-1 (ITSN1), which is recruited to the virus prior to its actin-based motility. Moreover, Cdc42, ITSN1 and N-WASP function collaboratively in a feed-forward loop to promote vaccinia-induced actin polymerisation. Outside the context of infection, we demonstrate that ITSN1 also functions together with Cdc42, Nck and N-WASP during phagocytosis mediated by the Fc gamma receptor. Our observations suggest that ITSN1 is an important general regulator of Cdc42-, Nck- and N-WASP-dependent actin polymerisation.


Assuntos
Actinas/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Proteínas Oncogênicas/metabolismo , Vaccinia virus/genética , Proteína Neuronal da Síndrome de Wiskott-Aldrich/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Actinas/ultraestrutura , Proteínas Adaptadoras de Transporte Vesicular/genética , Animais , Linhagem Celular , Proteína Adaptadora GRB2/genética , Humanos , Fosforilação , Transdução de Sinais/genética , Vaccinia virus/patogenicidade , Vaccinia virus/ultraestrutura , Proteína cdc42 de Ligação ao GTP/genética
17.
Nat Rev Microbiol ; 11(8): 551-60, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24020073

RESUMO

The role of clathrin in pathogen entry has received much attention and has highlighted the adaptability of clathrin during internalization. Recent studies have now uncovered additional roles for clathrin and have put the spotlight on its role in pathogen spread. Here, we discuss the manipulation of clathrin by pathogens, with specific attention to the processes that occur at the plasma membrane. In the majority of cases, both clathrin and the actin cytoskeleton are hijacked, so we also examine the interplay between these two systems and their role during pathogen internalization, egress and spread.


Assuntos
Actinas/metabolismo , Clatrina/metabolismo , Endocitose , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/microbiologia , Citoesqueleto de Actina/virologia , Animais , Aderência Bacteriana , Membrana Celular/metabolismo , Membrana Celular/microbiologia , Membrana Celular/virologia , Interações Hospedeiro-Patógeno , Transporte Proteico , Shigella flexneri/fisiologia , Vaccinia virus/fisiologia , Internalização do Vírus , Liberação de Vírus , Replicação Viral
18.
Cell Host Microbe ; 12(3): 346-59, 2012 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-22980331

RESUMO

During their egress, newly assembled vaccinia virus particles fuse with the plasma membrane and enhance their spread by inducing Arp2/3-dependent actin polymerization. Investigating the events surrounding vaccinia virus fusion, we discovered that vaccinia transiently recruits clathrin in a manner dependent on the clathrin adaptor AP-2. The recruitment of clathrin to vaccinia dramatically enhances the ability of the virus to induce actin-based motility. We demonstrate that clathrin promotes clustering of the virus actin tail nucleator A36 and host N-WASP, which activates actin nucleation through the Arp2/3 complex. Increased clustering enhances N-WASP stability, leading to more efficient actin tail initiation and sustained actin polymerization. Our observations uncover an unexpected role for clathrin during virus spread and have important implications for the regulation of actin polymerization.


Assuntos
Actinas/metabolismo , Clatrina/metabolismo , Multimerização Proteica , Vaccinia virus/patogenicidade , Complexo 2-3 de Proteínas Relacionadas à Actina , Células HeLa , Humanos , Proteína Neuronal da Síndrome de Wiskott-Aldrich
19.
EMBO J ; 30(22): 4523-38, 2011 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21915095

RESUMO

Transport of cargoes by kinesin-1 is essential for many cellular processes. Nevertheless, the number of proteins known to recruit kinesin-1 via its cargo binding light chain (KLC) is still quite small. We also know relatively little about the molecular features that define kinesin-1 binding. We now show that a bipartite tryptophan-based kinesin-1 binding motif, originally identified in Calsyntenin is present in A36, a vaccinia integral membrane protein. This bipartite motif in A36 is required for kinesin-1-dependent transport of the virus to the cell periphery. Bioinformatic analysis reveals that related bipartite tryptophan-based motifs are present in over 450 human proteins. Using vaccinia as a surrogate cargo, we show that regions of proteins containing this motif can function to recruit KLC and promote virus transport in the absence of A36. These proteins interact with the kinesin light chain outside the context of infection and have distinct preferences for KLC1 and KLC2. Our observations demonstrate that KLC binding can be conferred by a common set of features that are found in a wide range of proteins associated with diverse cellular functions and human diseases.


Assuntos
Cinesinas/metabolismo , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/metabolismo , Vaccinia virus/química , Vaccinia virus/fisiologia , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/metabolismo , Motivos de Aminoácidos , Transporte Biológico , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular , Genoma Humano , Genótipo , Células HeLa , Humanos , Cinesinas/química , Cinesinas/genética , Ligação Proteica , Estrutura Terciária de Proteína , Alinhamento de Sequência , Triptofano/química , Vaccinia virus/genética , Proteínas da Matriz Viral/genética , Liberação de Vírus
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